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Saturday, December 29, 2012

Book Review: Wheat Belly is a bestseller, but what's the science behind it?

If a doctor writes a book in the forest...
Wait a minute, that's not right.

If a doctor writes a book about health... is it science?

This is the question I had in mind while reading Wheat Belly. When a physician like William Davis, MD, takes time out of his (no doubt) busy schedule to write a health-related book, ideally he has taken the time to get familiar with all the scientific literature on the topic. This may be easier for doctors than for some other writers, as Davis may have had the benefit of hearing research summaries at conferences, or having literature reviews arrive on his desk with the daily mail. Add that to years of clinical experience, and you have the potential for a pretty compelling argument on a health issue.

But what if, instead, a doctor seems to have spent years giving a certain piece of unusual clinical advice about a dietary change. And he has had such great success with patients who follow that advice that he goes looking for science to explain why it works. He scraps together a few studies that he thinks are relevant, connects some dots, and writes a book. What then?

Interesting, but not necessarily science.

So here's the heads up: Wheat Belly is an example of the latter. Though Davis, a cardiologist, has written a very interesting book with a timely message, you should know that it is not strictly based on science. Meaning: there is little or no evidence for his claims about the ill health effects of wheat.

Case in point: the glycemic index stats he cites are from an article published in 1981 - and he repeats again and again that the study found a greater blood sugar rise with "whole-meal" bread than with white bread, even though - ahem - a fair amount of glycemic index research has been done since, and a quick visit to almost any diabetes association website will confirm that whole wheat breads (for the most part) have lower glycemic indices than white breads. Davis gives a few nods to how his claims fit in, or don't fit in, with the advice of professional bodies. But he doesn't present a complete picture of why and how science shows that eliminating wheat from one's diet is a good idea, because the scientific evidence doesn't exist at present.

The point of the book is that it's bad to eat things that spike your blood sugar - i.e. things with a high glycemic index (GI). Apparently wheat spikes the blood sugar more than you'd expect - the oft-cited study found whole grain bread had a GI of 72, while a Mars bar had a GI of only 68 - and therefore we should eliminate wheat.

It follows that we should eliminate all things that spike blood sugar. Davis advocates this. So properly, the book should be called "Carb Belly". (Of course, the arguments against carbs have been well-explored in books that promote the Atkins diet, Paleo diet, Specific Carbohydrate diet, etc.) But Davis says the one carbohydrate that people have the most trouble eliminating is wheat. Hence, the name Wheat Belly.

Here's what's in the book:

Part 1:
Davis explains how wheat strains have changed with hybridization and how modern types of wheat affect us in unprecedented ways.

Part 2:
Davis describes wheat's "head-to-toe destruction of health": (1) the addictive properties of wheat that can influence behaviour and mood, (2) the way wheat triggers blood sugar and insulin extremes, which lead to visceral fat accumulation, (3) how intestinal permeability triggered by a protein in gluten may be responsible for the rise of autoimmune disorders and digestive disorders, (4) an argument that wheat may cause type 2 diabetes, (5) an explanation of how wheat affects the body's pH, resulting in an "acid-rich situation" and that promotes osteoporosis, (6) wheat's promotion of AGEs, which signal aging, (7) how wheat leads to heart disease by increasing triglycerides that turn into atherosclerotic plaque, (8) how the immune system's attack on nerve cells results in cerebellar ataxia and brain fog, and (9) how increased levels of insulin, and an immune reaction to gluten, can show up as acne or skin rash.

Note that for most of these claims, Davis's evidence is in the realm of the "theoretically possible." As far as I can tell, the science actually addressing these claims is weak. The studies conducted on humans where all else is equal, except the inclusion of wheat in the diet, are rare. Making his claims premature at best.

Part 3:
He talks about the "how to" of eliminating wheat and other carbohydrates. The book includes menus and recipes for low-carb eating.

So now the question, can we really knock Dr. Davis for proposing a low-risk treatment that seems to work like magic clinically for a host of health problems? Can we truly fault a compelling book that's convinced a lot of people to do something that seems to improve their health? It doesn't escape me that it took a lot of bravery for him to so emphatically convey this message in a world that is very wheat-centred.

So yes, Davis has perhaps inspired many people to initiate a positive change for their health by penning a bestselling book with lots of media coverage. But by putting together a misleading scientific grab-bag for convincing people to make this change, he is ensuring they never fully understand what caused their complex health problems in the first place.

Very nice- I appreciate your perspective and insight into this topic. I think wheat deserves much of the heat it has gotten lately but I think it's true impact on people, like many of the other nutrition/food/health things, depends a lot on those little friends that inhabit the gut and all of the dynamic environment they call home. We are creatures of the natural world and, as you well know, we cannot consider our health or how anything impacts us (particularly food) without asking how it interacts with the gut. It does seem encouraging that as we "re"discover that "it's all about the gut" we will be able to get a little more clarity into things like wheat and just how impactful it might on a personal basis. Thanks for a nice critique and great blog, keep up the good work!

all I know is I feel great! Being diagnosed with Acid Reflux and going Gluten Free has improved this condition, not to mention an over all feeling of well being. I have more energy, have lost weight and will continue Gluten Free.

And what experience does she have other than writing? What scientific studies has she completed at university, what medical training. She is no more than a tweeter without any experience. The doctor has nothing to gain, and a lot to loose, because of his stance. And I have experienced first hand what he has stated, with a heart attack, and with my blood level shooting through the roof after eating anything with gluten on it and taking two days to come down again and having to take blood pressure prescriptions.

Yes, there is no complete review on effects of eating wheat but what Dr Davis has pointed out is from experiences which has more value than reviews. And motivation from experiences had let to write this book. I have also put my experiences in the book named 'How to lose your wheat belly' on Kindle.

Davis's point is that it is wheat specifically though. I followed his TYP blog for years wrt heart disease prevention and asked him repeatedly about wheat vs. low-carb, as I mostly low-carb anyways for T2 diabetes. Aside from known gluten sensitivity, he genuinely seemed to think that thickening a sauce with a TB of corn starch was better than using a TB of flour.

He has always said it is wheat specifically though he never had a good reason why when asked until this book, which seems to me to be convincing WHILE you're reading it. ;)

On the other hand, in the book he makes the point that replacing wheat with gluten-free foods is NOT the answer, so it does wind up just being low-carb after all. More to the point, he opposes most processed food, so it does wind up rather like Paleo.

IMO, a lot of his work other than wheat is more important - the use of niacin, vitamin D, vitamin K2, thyroid optimization, other hormones, etc. I've learned a lot from him, and while it isn't double-blind studies, he does see regression of coronary plaque with his protocol, which beats the heck out of most cardiologists. Not wanting another CABG, I find his work useful as he knows how to clean the pipes.

Wheat Belly has been much bigger than Track Your Plaque though as weight loss is sexier than preventing heart disease.

And he has some other stuff going on with the blog for WB, like playing with spelt and other old versions of wheat. Apparently, it is not specifically the gluten that bugs him.

On the other hand, while obviously Atkins is low carb, and Paleo practically seems to usually wind up low-carb in most cases, I don't think SCD is necessarily low-carb as SCD limits disaccharides and polysaccharides, but not monosaccharides.

Theoretically, you could do a high-carb SCD, and it would all be the highest GI carbs so the worst for bG control (which is usually the point of low-carb, bG and insulin).

SCD is specifically about only eating rapdily absorbed carbs, thus avoiding food that can act as prebiotics to starve out the bad bacteria.

I'm more familair with GAPS than SCD, but GAPs is built directly on SCD.

I've never quite understood how they are sure they're starving the bad bacteria and not the good ones though. I mean, they do a lot of probiotics, both supplements and fermented foods, so maybe the idea is to starve ALL gut bacteria and then replenish with new ones.

As a former Atkins aficionado, (the ketosis sucks) Wheat Belly is Atkins updated. However, though maybe not scientifically whole, the messages on diabetes, insulin resistance, and blood sugar spikes are dead on. At 59 years old since July of 2013, did 11 weeks of insanity, dumped all wheat from diet,now on weight training. Weight from 190 to 160. Off my high blood pressure medicine, bmi from 27.58 to 24.4, body fat percentage 26% to 18%. Wheat belly pretty much the Paleo diet with no wheat. Does work. Exercise a must, but a great exercise program can't beat a bad diet. Get fit people, old and decrepit is no way to die.